Editing Sonoluminescence

{{Short description|Light emissions from collapsing, sound-induced bubbles}}
[[File:Single bubble cropped.jpg|right|thumb|Single-bubble sonoluminescence – a single, cavitating bubble]]
'''Sonoluminescence''' is the emission of light from [[Implosion (mechanical process)|imploding]] [[Liquid bubble|bubble]]s in a liquid when excited by sound.

Sonoluminescence was first discovered in 1934 at the [[University of Cologne]]. It occurs when a sound wave of sufficient intensity induces a gaseous cavity within a liquid to collapse quickly, emitting a burst of light. The phenomenon can be observed in stable single-bubble sonoluminescence (SBSL) and multi-bubble sonoluminescence (MBSL). In 1960, Peter Jarman proposed that sonoluminescence is thermal in origin and might arise from microshocks within collapsing cavities. Later experiments revealed that the [[temperature]] inside the bubble during SBSL could reach up to {{Convert|12000|K|C F|lk=in|abbr=out}}. The exact mechanism behind sonoluminescence remains unknown, with various hypotheses including hotspot, ''[[bremsstrahlung]]'', and collision-induced radiation. Some researchers have even speculated that temperatures in sonoluminescing systems could reach millions of kelvins, potentially causing thermonuclear fusion; this idea, however, has been met with skepticism by other researchers.<ref name="Scientific American 1999">{{cite web | title=The bubbles produced by ultrasound in water (sonoluminescence) reach extremely high temperatures and pressures for brief periods. Could these conditions initiate or facilitate nuclear fusion, as suggested in the recent movie "Chain Reaction"? | website=Scientific American | date=1999-10-21 | url=https://www.scientificamerican.com/article/the-bubbles-produced-by-u/ | access-date=2023-05-12}}</ref> The phenomenon has also been observed in nature, with the [[pistol shrimp]] being the first known instance of an animal producing light through sonoluminescence.<ref name="Patek and Caldwell">{{cite journal |author1=S. N. Patek |author2=R. L. Caldwell |year=2005 |journal=[[The Journal of Experimental Biology]] |volume=208 |issue=19 |pages=3655–3664 |title=Extreme impact and cavitation forces of a biological hammer: strike forces of the peacock mantis shrimp |doi=10.1242/jeb.01831 |pmid=16169943|s2cid=312009 |url=https://escholarship.org/content/qt9938507n/qt9938507n.pdf?t=lnr7mv |doi-access=free }}</ref>

==History==
The sonoluminescence effect was first discovered at the [[University of Cologne]] in 1934 as a result of work on [[sonar]].<ref>{{Cite journal | vauthors = Farley J, Hough S |title=Single Bubble Sonoluminsescence|journal= APS Northwest Section Meeting Abstracts|pages= D1.007|date=2003|bibcode=2003APS..NWS.D1007F}}</ref> [[Hermann Frenzel]] and H. Schultes put an ultrasound [[transducer]] in a tank of photographic [[developer fluid]]. They hoped to speed up the development process. Instead, they noticed tiny dots on the film after developing and realized that the bubbles in the fluid were emitting light with the ultrasound turned on.<ref>H. Frenzel and H. Schultes, ''Luminescenz im ultraschallbeschickten Wasser'' Zeitschrift für Physikalische Chemie International journal of research in physical chemistry and chemical physics, Published Online: 2017-01-12 | DOI: https://doi.org/10.1515/zpch-1934-0137</ref> It was too difficult to analyze the effect in early experiments because of the complex environment of a large number of short-lived bubbles. This phenomenon is now referred to as multi-bubble sonoluminescence (MBSL).

In 1960, Peter Jarman from [[Imperial College London|Imperial College of London]] proposed the most reliable theory of sonoluminescence phenomenon. He concluded that sonoluminescence is basically thermal in origin and that it might possibly arise from microshocks with the collapsing cavities.<ref>{{Cite journal|last=Jarman|first=Peter|date=1960-11-01|title=Sonoluminescence: A Discussion|journal=The Journal of the Acoustical Society of America|volume=32|issue=11|pages=1459–1462|doi=10.1121/1.1907940|bibcode=1960ASAJ...32.1459J|issn=0001-4966}}</ref>

In 1990, an experimental advance was reported by Gaitan and Crum, who produced stable single-bubble sonoluminescence (SBSL).<ref name="Crum Cordry 1994 pp. 287–297">{{cite book | last1=Crum | first1=Lawrence A. | last2=Cordry | first2=Sean | title=Fluid Mechanics and Its Applications | chapter=Single-bubble sonoluminescence | publisher=Springer Netherlands | publication-place=Dordrecht | year=1994 | isbn=978-94-010-4404-2 | issn=0926-5112 | doi=10.1007/978-94-011-0938-3_27 | pages=287–297}}</ref> In SBSL, a single bubble trapped in an acoustic standing wave emits a pulse of light with each compression of the bubble within the [[standing wave]]. This technique allowed a more systematic study of the phenomenon because it isolated the complex effects into one stable, predictable bubble. It was realized that the [[temperature]] inside the bubble was hot enough to melt [[steel]], as seen in an experiment done in 2012; the temperature inside the bubble as it collapsed reached about {{Convert|12000|K|C F|lk=in}}.<ref>{{cite journal | vauthors = Ndiaye AA, Pflieger R, Siboulet B, Molina J, Dufrêche JF, Nikitenko SI | title = Nonequilibrium vibrational excitation of OH radicals generated during multibubble cavitation in water | journal = The Journal of Physical Chemistry A | volume = 116 | issue = 20 | pages = 4860–7 | date = May 2012 | pmid = 22559729 | doi = 10.1021/jp301989b | bibcode = 2012JPCA..116.4860N }}</ref> Interest in sonoluminescence was renewed when an inner temperature of such a bubble well above {{Convert|1|MK|C F|lk=in}} was postulated.<ref>{{Cite journal|last1=Moss|first1=William C.|last2=Clarke|first2=Douglas B.|last3=White|first3=John W.|last4=Young|first4=David A.|date=September 1994|title=Hydrodynamic simulations of bubble collapse and picosecond sonoluminescence|journal=Physics of Fluids|volume=6|issue=9|pages=2979–2985|doi=10.1063/1.868124|issn=1070-6631|bibcode=1994PhFl....6.2979M}}</ref> This temperature is thus far not conclusively proven; rather, recent experiments indicate temperatures around {{convert|20000|K|C F}}.<ref name=Illinois/>

==Properties==
[[Image:Sonoluminescence.jpg|right|thumb|Long exposure image of MBSL created by a high-intensity [[Ultrasound|ultrasonic]] horn immersed in a beaker of liquid]]

Sonoluminescence can occur when a sound wave of sufficient intensity induces a gaseous cavity within a liquid to collapse quickly. This cavity may take the form of a preexisting bubble or may be generated through a process known as [[cavitation]]. Sonoluminescence in the laboratory can be made to be stable so that a single bubble will expand and collapse over and over again in a periodic fashion, emitting a burst of light each time it collapses. For this to occur, a standing [[acoustic wave]] is set up within a liquid, and the bubble will sit at a pressure [[antinode]] of the standing wave. The [[frequencies]] of [[resonance]] depend on the shape and size of the container in which the bubble is contained.

Some facts about sonoluminescence:{{Citation needed|date=January 2016}}
* The light that flashes from the bubbles last between 35 and a few hundred [[picosecond]]s long, with peak intensities of the order of {{Convert|1|–|10|MW|lk=on|hp}}.
* The bubbles are very small when they emit light—about {{Convert|1|μm|in|lk=in|sp=us}} in diameter—depending on the ambient fluid (e.g., water) and the gas content of the bubble (e.g., [[atmospheric air]]).
* SBSL pulses can have very stable periods and positions. In fact, the frequency of light flashes can be more stable than the rated frequency stability of the oscillator making the sound waves driving them. The stability analyses of the bubble, however, show that the bubble itself undergoes significant geometric instabilities due to, for example, the [[Bjerknes force]]s and [[Rayleigh–Taylor instabilities]].
* The addition of a small amount of [[noble gas]] (such as [[helium]], [[argon]], or [[xenon]]) to the gas in the bubble increases the intensity of the emitted light.<ref name="Hiller Weninger Putterman Barber 1994 pp. 248–250">{{cite journal | last1=Hiller | first1=Robert | last2=Weninger | first2=Keith | last3=Putterman | first3=Seth J. | last4=Barber | first4=Bradley P. | title=Effect of Noble Gas Doping in Single-Bubble Sonoluminescence | journal=Science | publisher=American Association for the Advancement of Science | volume=266 | issue=5183 | year=1994 | issn=0036-8075 | jstor=2884762 | pages=248–250 | doi=10.1126/science.266.5183.248 | pmid=17771443 | bibcode=1994Sci...266..248H | url=http://www.jstor.org/stable/2884762 | access-date=12 May 2023}}</ref>

Spectral measurements have given bubble temperatures in the range from {{Convert|2300|to|5100|K|C F}}, the exact temperatures depending on experimental conditions including the composition of the liquid and gas.<ref name=flannigan>{{cite journal | vauthors = Didenko YT, McNamara WB, Suslick KS | title = Effect of noble gases on sonoluminescence temperatures during multibubble cavitation | journal = Physical Review Letters | volume = 84 | issue = 4 | pages = 777–80 | date = January 2000 | pmid = 11017370 | doi = 10.1103/PhysRevLett.84.777 | bibcode = 2000PhRvL..84..777D }}</ref> Detection of very high bubble temperatures by spectral methods is limited due to the opacity of liquids to short wavelength light characteristic of very high temperatures.

A study describes a method of determining temperatures based on the formation of [[Plasma (physics)|plasmas]]. Using argon bubbles in [[sulfuric acid]], the data shows the presence of ionized molecular oxygen {{Chem|O|2|+}}, [[sulfur monoxide]], and atomic argon populating high-energy excited states, which confirms a hypothesis that the bubbles have a hot plasma core.<ref>{{cite journal | vauthors = Flannigan DJ, Suslick KS | title = Plasma formation and temperature measurement during single-bubble cavitation | journal = Nature | volume = 434 | issue = 7029 | pages = 52–5 | date = March 2005 | pmid = 15744295 | doi = 10.1038/nature03361 | bibcode = 2005Natur.434...52F | s2cid = 4318225 | url = https://zenodo.org/record/895438 }}</ref> The [[ionization]] and [[Excited state|excitation]] energy of [[Ozonide|dioxygenyl]] [[cations]], which they observed, is {{Convert|18|eV|J|lk=in}}. From this observation, they conclude the core temperatures reach at least {{convert|20000|K|C F}}<ref name=Illinois>{{cite web|url=http://news.illinois.edu/news/05/0302bubbles.html |title=Temperature inside collapsing bubble four times that of sun &#124; Archives &#124; News Bureau &#124; University of Illinois |publisher=News.illinois.edu |date=2005-02-03 |access-date=2012-11-14}}</ref>—hotter than the surface of the [[Sun]].

==Rayleigh–Plesset equation==
:{{Main|Rayleigh–Plesset equation}}
The dynamics of the motion of the bubble is characterized to a first approximation by the Rayleigh–Plesset equation (named after [[John Strutt, 3rd Baron Rayleigh|Lord Rayleigh]] and [[Milton S. Plesset|Milton Plesset]]):

:<math>R\ddot{R} + \frac{3}{2}\dot{R}^{2} = \frac{1}{\rho}\left(P_\infty(t) - P_0(t) - 4\mu\frac{\dot{R}}{R} - \frac{2\gamma}{R}\right)</math>

This is an approximate equation that is derived from the [[Navier–Stokes equations]] (written in [[spherical coordinate system]]) and describes the motion of the radius of the bubble ''R'' as a function of time ''t''. Here, ''μ'' is the [[viscosity]], ''<math>P_\infty(t)</math>'' is the external [[pressure]] infinitely far from the bubble, ''<math>P_0(t)</math>'' is the internal [[pressure]] of the bubble, <math>\rho</math> is the liquid density, and ''γ'' is the [[surface tension]]. The over-dots represent time derivatives. This equation, though approximate, has been shown to give good estimates on the motion of the bubble under the [[acoustics|acoustically]] driven field except during the final stages of collapse. Both simulation and experimental measurement show that during the critical final stages of collapse, the bubble wall velocity exceeds the speed of sound of the gas inside the bubble.<ref name="pmid10046927">{{cite journal |vauthors=Barber BP, Putterman SJ | title = Light scattering measurements of the repetitive supersonic implosion of a sonoluminescent bubble | journal = Physical Review Letters | volume = 69 | issue = 26 | pages = 3839–3842 | date = December 1992 | pmid = 10046927 | doi = 10.1103/PhysRevLett.69.3839 | bibcode = 1992PhRvL..69.3839B }}</ref> Thus a more detailed analysis of the bubble's motion is needed beyond Rayleigh–Plesset to explore the additional energy focusing that an internally formed shock wave might produce. In the static case, the Rayleigh-Plesset equation simplifies, yielding the [[Young–Laplace equation]].

==Mechanism of phenomena==
{{Main|Mechanism of sonoluminescence}}
The mechanism of the phenomenon of sonoluminescence is unknown. [[Hypothesis|Hypotheses]] include: hotspot, [[Bremsstrahlung|bremsstrahlung radiation]], collision-induced radiation and [[corona discharge]]s, [[nonclassical light]], [[Quantum tunneling |proton tunneling]], [[electrodynamic]] [[Jet (fluid)|jets]] and [[fractoluminescence|fractoluminescent jets]] (now largely discredited due to contrary experimental evidence).{{citation needed|date=August 2015}}

[[Image:Sonoluminescence.png|center|600px|thumb|From left to right: apparition of bubble, slow expansion, quick and sudden contraction, emission of light]]

In 2002, M. Brenner, S. Hilgenfeldt, and D. Lohse published a 60-page review that contains a detailed explanation of the mechanism.<ref>{{cite journal | vauthors = Brenner MP, Hilgenfeldt S, Lohse D | title = Single-bubble sonoluminescence. | journal = Reviews of Modern Physics | date = May 2002 | volume = 74 | issue = 2 | pages = 425–484 | doi = 10.1103/RevModPhys.74.425 | url = https://research.utwente.nl/en/publications/single-bubble-sonoluminescence(ef18245b-e923-4f90-a6be-7b1189c34232).html | bibcode = 2002RvMP...74..425B }}</ref> An important factor is that the bubble contains mainly inert noble gas such as argon or xenon (air contains about 1% argon, and the amount dissolved in water is too great; for sonoluminescence to occur, the concentration must be reduced to 20–40% of its equilibrium value) and varying amounts of [[water vapor]]. Chemical reactions cause [[nitrogen]] and [[oxygen]] to be removed from the bubble after about one hundred expansion-collapse cycles. The bubble will then begin to emit light.<ref>{{cite journal | vauthors = Matula TJ, Crum LA | title = Evidence for gas exchange in single-bubble sonoluminescence. | journal = Physical Review Letters | date = January 1998 | volume = 80 | issue = 4 | pages = 865–868 | doi = 10.1103/PhysRevLett.80.865 | bibcode = 1998PhRvL..80..865M }}</ref> The light emission of highly compressed noble gas is exploited technologically in the [[argon flash]] devices.

During bubble collapse, the inertia of the surrounding water causes high pressure and high temperature, reaching around 10,000 kelvins in the interior of the bubble, causing the ionization of a small fraction of the noble gas present. The amount ionized is small enough for the bubble to remain transparent, allowing volume emission; surface emission would produce more intense light of longer duration, dependent on [[wavelength]], contradicting experimental results. Electrons from ionized atoms interact mainly with neutral atoms, causing thermal bremsstrahlung radiation. As the wave hits a low energy trough, the pressure drops, allowing electrons to [[Carrier generation and recombination|recombine]] with atoms and light emission to cease due to this lack of free electrons. This makes for a 160-picosecond light pulse for argon (even a small drop in temperature causes a large drop in ionization, due to the large [[ionization energy]] relative to photon energy). This description is simplified from the literature above, which details various steps of differing duration from 15 microseconds (expansion) to 100 picoseconds (emission).

Computations based on the theory presented in the review produce radiation parameters (intensity and duration time versus wavelength) that match experimental results{{citation needed|date=January 2015}} with errors no larger than expected due to some simplifications (e.g., assuming a uniform temperature in the entire bubble), so it seems the phenomenon of sonoluminescence is at least roughly explained, although some details of the process remain obscure.

Any discussion of sonoluminescence must include a detailed analysis of metastability. Sonoluminescence in this respect is what is physically termed a bounded phenomenon meaning that the sonoluminescence exists in a bounded region of parameter space for the bubble; a coupled magnetic field being one such parameter. The magnetic aspects of sonoluminescence are very well documented.<ref>{{cite journal | vauthors = Young JB, Schmiedel T, Kang W | title = Sonoluminescence in high magnetic fields. | journal = Physical Review Letters | date = December 1996 | volume = 77 | issue = 23 | pages = 4816–4819 | doi = 10.1103/PhysRevLett.77.4816 | pmid = 10062638 | bibcode = 1996PhRvL..77.4816Y }}</ref>

===Other proposals===

====Quantum explanations====
An unusually exotic hypothesis of sonoluminescence, which has received much popular attention, is the Casimir energy hypothesis suggested by noted physicist [[Julian Schwinger]]<ref>{{cite web | first = Julian | last = Schwinger | name-list-style = vanc |url=http://www.infinite-energy.com/iemagazine/issue1/colfusthe.html |title= Cold Fusion: A History of Mine |publisher=Infinite-energy.com |date=1989-03-23 |access-date=2012-11-14}}</ref> and more thoroughly considered in a paper by [[Claudia Eberlein]]<ref>{{cite journal | vauthors = Eberlein C | title = Theory of quantum radiation observed as sonoluminescence. | journal = Physical Review A | date = April 1996 | volume = 53 | issue = 4 | pages = 2772–2787 | doi = 10.1103/PhysRevA.53.2772| pmid = 9913192 | url = https://pdfs.semanticscholar.org/27f5/25c6fca3f8eff0605a6f71c75ce2a677ce7e.pdf | archive-url = https://web.archive.org/web/20190323091226/https://pdfs.semanticscholar.org/27f5/25c6fca3f8eff0605a6f71c75ce2a677ce7e.pdf | url-status = dead | archive-date = 2019-03-23 | bibcode = 1996PhRvA..53.2772E | arxiv = quant-ph/9506024 | s2cid = 10902274 }}</ref> of the [[University of Sussex]]. Eberlein's paper suggests that the light in sonoluminescence is generated by the vacuum within the bubble in a process similar to [[Hawking radiation]], the radiation generated at the [[event horizon]] of [[black hole]]s. According to this vacuum energy explanation, since quantum theory holds that vacuum contains [[virtual particle]]s, the rapidly moving interface between water and gas converts virtual photons into real photons. This is related to the [[Unruh effect]] or the [[Casimir effect]]. The argument has been made that sonoluminescence releases too large an amount of energy and releases the energy on too short a time scale to be consistent with the vacuum energy explanation,<ref>{{cite arXiv | vauthors = Milton KA | title = Dimensional and Dynamical Aspects of the Casimir Effect: Understanding the Reality and Significance of Vacuum Energy | date = September 2000 | eprint = hep-th/0009173 }}</ref> although other credible sources argue the vacuum energy explanation might yet prove to be correct.<ref>{{cite arXiv | vauthors = Liberati S, Belgiorno F, Visser M | title = Comment on "Dimensional and dynamical aspects of the Casimir effect: understanding the reality and significance of vacuum energy" | eprint = hep-th/0010140v1 | year = 2000 }}</ref>

====Nuclear reactions====
{{Main|Bubble fusion}}
Some have argued that the Rayleigh–Plesset equation described above is unreliable for predicting bubble temperatures and that actual temperatures in sonoluminescing systems can be far higher than 20,000 kelvins. Some research claims to have measured temperatures as high as 100,000 kelvins and speculates temperatures could reach into the millions of kelvins.<ref name="pmid18851095">{{cite journal | vauthors = Chen W, Huang W, Liang Y, Gao X, Cui W | title = Time-resolved spectra of single-bubble sonoluminescence in sulfuric acid with a streak camera | journal = Physical Review E | volume = 78 | issue = 3 Pt 2 | pages = 035301 | date = September 2008 | pmid = 18851095 | doi = 10.1103/PhysRevE.78.035301 | bibcode = 2008PhRvE..78c5301C }}
*{{cite web |author=Tim Reid |date=15 October 2008 |title=Sonoluminescence: Baking bubbles |website=Nature China |url=http://www.nature.com/nchina/2008/081015/full/nchina.2008.241.html |archive-url=https://web.archive.org/web/20131212070822/http://www.nature.com/nchina/2008/081015/full/nchina.2008.241.html |archive-date=2013-12-12}}</ref> Temperatures this high could cause [[thermonuclear fusion]]. This possibility is sometimes referred to as [[bubble fusion]] and is likened to the implosion design used in the fusion component of [[thermonuclear weapon]]s.

Experiments in 2002 and 2005 by [[Rusi Taleyarkhan|R. P. Taleyarkhan]] using deuterated [[acetone]] showed measurements of [[tritium]] and neutron output consistent with fusion. However, the papers were considered low quality and there were doubts cast by a report about the author's scientific misconduct. This made the report lose credibility among the scientific community.<ref name="latimes">[http://www.latimes.com/news/nationworld/nation/la-sci-misconduct19-2008jul19,0,1765099.story Purdue physicist found guilty of misconduct], Los Angeles Times, July 19, 2008, Thomas H. Maugh II</ref><ref name="Nature_India_2008">{{cite journal | vauthors = Jayaraman KS | title = Bubble fusion discoverer says his science is vindicated | journal = [[Nature India]] | doi = 10.1038/nindia.2008.271 | year = 2008 }}</ref><ref name="SFC">{{cite news | agency=Associated Press | url = https://www.usatoday.com/tech/science/2008-08-27-purdue-scientist_N.htm | title = Purdue reprimands fusion scientist for misconduct | work=USA Today | date = August 27, 2008 | access-date = 2010-12-28 }}</ref>

On January 27, 2006, researchers at [[Rensselaer Polytechnic Institute]] claimed to have produced fusion in sonoluminescence experiments.<ref>{{cite web|url=http://news.rpi.edu/luwakkey/1322 |title=RPI: News & Events – New Sonofusion Experiment Produces Results Without External Neutron Source |publisher=News.rpi.edu |date=2006-01-27 |access-date=2012-11-14}}</ref><ref>{{cite web|url=https://www.sciencedaily.com/releases/2006/01/060130155542.htm |title=Using Sound Waves To Induce Nuclear Fusion With No External Neutron Source |publisher=Sciencedaily.com |date=2006-01-31 |access-date=2012-11-14}}</ref>

==Biological sonoluminescence==
<!-- This section is linked from [[Optical phenomenon]] -->
[[Alpheidae|Pistol shrimp]] (also called ''snapping shrimp'') produce a type of cavitation luminescence from a collapsing bubble caused by quickly snapping its claw. The animal snaps a specialized claw shut to create a cavitation bubble that generates acoustic pressures of up to 80 kPa at a distance of 4&nbsp;cm from the claw. As it extends out from the claw, the bubble reaches speeds of 60 miles per hour (97&nbsp;km/h) and releases a sound reaching 218 decibels. The pressure is strong enough to kill small fish. The light produced is of lower intensity than the light produced by typical sonoluminescence and is not visible to the naked eye. The light and heat produced by the bubble may have no direct significance, as it is the shockwave produced by the rapidly collapsing bubble which these shrimp use to stun or kill prey. However, it is the first known instance of an animal producing light by this effect and was whimsically dubbed "shrimpoluminescence" upon its discovery in 2001.<ref>{{cite journal | vauthors = Lohse D, Schmitz B, Versluis M | title = Snapping shrimp make flashing bubbles | journal = Nature | volume = 413 | issue = 6855 | pages = 477–8 | date = October 2001 | pmid = 11586346 | doi = 10.1038/35097152 | bibcode = 2001Natur.413..477L | s2cid = 4429684 }}</ref> It has subsequently been discovered that another group of crustaceans, the [[mantis shrimp]], contains species whose club-like forelimbs can strike so quickly and with such force as to induce sonoluminescent cavitation bubbles upon impact.<ref name="Patek and Caldwell"/>

A mechanical device with 3D printed snapper claw at five times the actual size was also reported to emit light in a similar fashion,<ref>{{cite web | first = Emily | last = Conover | name-list-style = vanc | date = 15 March 2019 | title = Some shrimp make plasma with their claws. Now a 3-D printed claw can too | url = https://www.sciencenews.org/article/3d-printed-shrimp-claw-make-plasma | work = ScienceNews }}</ref> this bioinspired design was based on the snapping shrimp snapper claw molt shed from an ''Alpheus formosus'', the striped snapping shrimp.<ref>{{cite journal | vauthors = Tang X, Staack D | title = Bioinspired mechanical device generates plasma in water via cavitation | journal = Science Advances | volume = 5 | issue = 3 | pages = eaau7765 | date = March 2019 | pmid = 30899783 | pmc = 6420313 | doi = 10.1126/sciadv.aau7765 | bibcode = 2019SciA....5.7765T }}</ref>

==See also==
* [[List of light sources]]
* [[Seth Putterman]]
* [[Sonochemistry]]
* [[Triboluminescence]]

==References==
{{Reflist}}

==Further reading==
{{refbegin|30em}}
* {{cite journal | vauthors = Frenzel H, Schultes H | title = Luminescenz im ultraschallbeschickten Wasser | trans-title = Luminescence in ultra-hot water | language = de | journal = Zeitschrift für Physikalische Chemie | date = October 1934 | volume = 27 | issue = 1 | pages = 421–4 | doi = 10.1515/zpch-1934-0137 | s2cid = 100000845 }}
* {{cite journal | vauthors = Gaitan DF, Crum LA, Church CC, Roy RA | title = Sonoluminescence and bubble dynamics for a single, stable, cavitation bubble. | journal = The Journal of the Acoustical Society of America | date = June 1992 | volume =91 | issue = 6 | pages = 3166–83 | doi = 10.1121/1.402855 | bibcode = 1992ASAJ...91.3166G | s2cid = 122235287 | url = https://ora.ox.ac.uk/objects/uuid:e83dd48c-4340-48e0-aab2-140cc9d2c463 }}
* {{cite journal | vauthors = Brenner MP, Hilgenfeldt S, Lohse D | date = May 2002 | title = Single bubble sonoluminescence | journal = Reviews of Modern Physics | volume = 74 | issue = 2 | pages = 425–484 | doi = 10.1103/RevModPhys.74.425 | url = http://doc.utwente.nl/42577/1/single-bubble_sonoluminescence.pdf | bibcode=2002RvMP...74..425B }}
* {{cite journal | vauthors = Taleyarkhan RP, West CD, Cho JS, Lahey RT, Nigmatulin RI, Block RC | title = Evidence for nuclear emissions during acoustic cavitation | journal = Science | volume = 295 | issue = 5561 | pages = 1868–73 | date = March 2002 | pmid = 11884748 | doi = 10.1126/science.1067589 | url = http://www.sciencemag.org/feature/data/hottopics/bubble/index.shtml | author-link = Rusi Taleyarkhan | bibcode = 2002Sci...295.1868T | s2cid = 11405525 }}
* {{cite news |url=https://www.nytimes.com/2005/03/15/science/15soni.html |title=Tiny Bubbles Implode With the Heat of a Star |work=New York Times |date=March 15, 2005 | first = Kenneth | last = Chang | name-list-style = vanc }}
* {{cite book | vauthors = Wrbanek JD, Fralick GC, Wrbanek SY, Hall NC | chapter = Investigating sonoluminescence as a means of energy harvesting. | title = Frontiers of propulsional science | publisher = American Inst. of Aeronautics and Astronautics | series = Abstract NASA Technical Reports Server | date = 2009 | pages = 605–37 | isbn = 978-1-56347-956-4 | doi = 10.2514/4.479953 | editor1-last = Millis | editor1-first = Marc G | editor2-last = Davis | editor2-first = Eric W }}
* For a "How to" guide for student science projects see: {{cite journal
 | first1 = Robert | last1 = Hiller | first2 = Bradley | last2 = Barber | name-list-style = vanc |year = 1995 |title = Producing Light from a Bubble of Air |journal = Scientific American |volume = 272 |issue = 2 |pages = 96–98 |doi = 10.1038/scientificamerican0295-96|bibcode = 1995SciAm.272b..96H }}
* {{cite journal |first = Paweł |last = Tatrocki | name-list-style = vanc |year = 2006 |title = Difficulties in Sonoluminescence Theory Based on Quantum Phenomenon of Vacuum Radiation |website = PHILICA.com |id = Article number 19 |url = http://philica.com/display_article.php?article_id=19
}} This article was created in 1996 together with the alternative theory; both were seen by Ms Eberlein. It contains many references to the crucial experimental results in this field.
* {{cite arXiv | vauthors = Buzzacchi M, Del Giudice E, Preparata G | title = Sonoluminescence unveiled? | eprint=quant-ph/9804006 | date = April 1998 }}
{{refend}}

==External links==
{{Wiktionary}}
{{Commons category|Sonoluminescence}}
* [http://www.techmind.org/sl/ Detailed description of a sonoluminescence experiment]
* [https://web.archive.org/web/20080406115156/http://www.geocities.com/hbomb41ca/sono.html A description of the effect and experiment, with a diagram of the apparatus]
* [http://www.scs.uiuc.edu/suslick/images/matula.singlebubble.2cycles.mpg An mpg video of the collapsing bubble (934 kB)]
* [http://stilton.tnw.utwente.nl/shrimp/ Shrimpoluminescence] {{Webarchive|url=https://web.archive.org/web/20050313093555/http://stilton.tnw.utwente.nl/shrimp/ |date=2005-03-13 }}
* [http://www.impulsedevices.com/ Impulse Devices]
* [http://www.chm.bris.ac.uk/webprojects2004/eaimkhong/sonoluminescence.htm Applications of sonochemistry]
* [http://physicsworld.com/cws/article/news/5032 Sound waves size up sonoluminescence] {{Webarchive|url=https://web.archive.org/web/20110306162942/http://physicsworld.com/cws/article/news/5032 |date=2011-03-06 }}
* [http://www.physics.ucla.edu/Sonoluminescence/sono.pdf Sonoluminescence: Sound into light]

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